Propshaft phase.

[Slunnie]

I've just been reading that the front Rover propshafts are designed to be out of phase. 15 degrees or 2 splines from what I've been told and read.

I have (1 year ago ) rejigged the back of the Disco to replace the rubber couplng with a CV-CV tailshaft. Are the Uni's supposed to be in phase or are these meant to be thrown out of phase by a certain angle also?

[daddylonglegs]

The rear propshaft uJ's are meant to be in phase but on modified vehicles with big suspension lifts you can reduce the overall U joint angle by tilting the diff up at the front, then you can experiment with different phasing to acheive optimum balance.
Bill.

[Slunnie]

Thanks for this Bill. Its a 4" lift Disco2 with a radius arm rear end which points the pinion to the t/f case and so probably should be running a double cardin anyway. The Unis have been run aligned, though I think the vibs now may be coming from a loose slip joint. I've just tried rotating the the shaft by 1 spline and the vibrations still come at the same speeds. Time to go shopping I guess to get a tailshaft made up.

[daddylonglegs]

Keep trying 1 spline at a time until you end up back where you started I found a good compromise with a short shaft on an 88 inch wheelbase with 110 Salisbury rear and high suspension.
Bill.

[Bush65]

Slunnie,

You said replaced with a cv-cv tailshaft. Then later you said the pinion points to the t/f case.

By cv-cv tailshaft, do you mean you have a double cardin cv at both ends of the tailshaft?

If the pinion is pointing to the t/f case, theoretically, there would be no angle at the rear uni/cv so changing phase at slip joint wouldn't make any diff.

[Slunnie]

Gday John, sorry you're right, I wasn't all that clear.

The tailshaft I'm using now came from a Disco1 that has a single uni at each end, not a CV at all. The pinion does point at the transfer case though.

Ah, John. I'm feeling really dumb right at the moment. You are absolutely correct, making sense and have probably hit the nail on the head! Double cardin at the transfer case and uni at the diff is what it will have to be then. Good man, thanks for this.

[Slunnie]

On the other hand I wonder why it never vibrated with the single uni and rubber coupling? Time for a new tailshaft anyway I guess.

[HSV Rangie]

Correct set up for drive shaft excluding setting up out of pahse.


diff pinion paralel to each other single uni at each end.


Diff pinion pointing at t/case pinion single uni at diff and double cardan at t/case end.


Michael.